Coffee is actually a drink made of roasted, ground and brewed coffee beans. It has a long drinking history all over the world and is one of the most popular drinks in the world. Although the per capita coffee consumption in China is much lower than that in the above countries or regions, the number of coffee drinkers is growing rapidly and there are many coffee lovers. There are various folk sayings about coffee, such as "coffee causes cancer", "coffee is bad for the heart", and some people say that "coffee can refresh" and "coffee is good for the cardiovascular system" and so on. So what is the truth? In fact, ordinary people are also dubious, because there is no energy to verify, so there are different opinions about the advantages and disadvantages of coffee. The research paper points out that caffeine will affect people's intelligence. The average American adult consumes 300 milligrams of caffeine a day, which is equivalent to two cups of coffee. This level of caffeine intake will have a positive impact on people.

Low doses of caffeine can make people clear-headed and quick-thinking. However, large doses of caffeine can have negative effects, making people anxious and overexcited. But at the same time, he also shows that this negative effect will not pose a threat to human health, nor will it be addictive. In fact, compared with addictive substances such as alcohol and nicotine, caffeine (an important component of coffee) has a relatively mild effect. He also pointed out in his paper that there is a clear difference between physical dependence on a substance and actual addiction. Although millions of people in the United States say that coffee is indispensable, in his view, it is not an addiction, but a physiological dependence. In other words, if they stop drinking coffee, they may have withdrawal symptoms such as drowsiness and headache, but it is not impossible to quit. People can still give up gradually and the withdrawal symptoms can be improved.

As far as pregnant women are concerned, it is known that pregnant women should not drink coffee. If they drink coffee, they shouldn't drink more than 2 cups a day. Although Health Canada, American Obstetrics and Gynecology Association, American Obstetrics and Gynecology Association and other institutions believe that a small amount of coffee can be drunk during pregnancy, pregnant women should not be encouraged to drink coffee. Although there is no evidence that coffee can cause human congenital defects, I personally think that it is best to control the intake of coffee during pregnancy within two cups until further research proves that coffee is a completely nutritious and safe drink for pregnant women. Moreover, according to the metabolic pathway of its main component in human body, caffeine can enter breast milk, so high dose of caffeine may cause babies to wake up easily and feel uncomfortable during sleep.

Therefore, the American Academy of Pediatrics suggests that lactating women should also limit caffeine intake, but it also says that drinking a cup of coffee every day by lactating mothers will not have any effect on their babies. For children and adolescents, it is recommended that children and adolescents control caffeine intake. Parents can help their children control caffeinated drinks, such as coffee and tea. The American Academy of Pediatrics advises children and teenagers not to drink coffee. At the same time, the US Food and Drug Administration, EU Food Safety Agency, Health Canada, ANZ Food Standards Bureau and other institutions believe that it is safe for children and adolescents to consume less than 2.5~3 milligrams of caffeine per kilogram of body weight every day. To sum up, some special people need to pay attention to several matters needing attention. Ordinary people drinking coffee will not threaten our health.